Turbomachines can include a compressor portion linked to a turbine portion through a common compressor/turbine shaft and a combustor assembly. An inlet airflow can pass through an air intake toward the compressor portion. In the compressor portion, the inlet airflow can be compressed through a number of sequential stages toward the combustor assembly. In the combustor assembly, the compressed airflow can mix with fuel to form a combustible mixture. The combustible mixture can be combusted in the combustor assembly to form hot gases. The hot gases can be guided along a hot gas path of the turbine portion through a transition piece. The hot gases can expand along a hot gas path through a number of turbine stages acting upon turbine bucket airfoils mounted on wheels to create work that is output, for example, to power a generator. The hot gases can pass from the turbine portion through an exhaust system as exhaust gases. A number of thermocouples can be arranged in the exhaust system to measure temperatures of the exhaust gases.
The temperatures of the exhaust gases measured by the thermocouples can form an exhaust profile. The exhaust profile can be used to assess the health of combustion hardware. Certain hardware issues may cause a combustor to run unusually hot or cold, which can disrupt the typical exhaust profile. An atypical exhaust profile pattern may indicate an abnormal operation of one or more combustors. The typical exhaust profile for some turbomachines is uniform, where the individual exhaust thermocouples deviate only slightly from the mean. For such turbomachines, detection of combustion hardware anomalies can be performed by identifying thermocouple groups that deviate significantly from the mean. Other turbomachines may have an exhaust profile that has a peak-trough pattern during normal operation. Typically, a number of peaks and a number of troughs in the peak-trough pattern correspond to the number of combustors of the turbomachine. The approach described above may not be effective at detecting combustion anomalies for turbomachines with a peak-trough pattern since the peak-trough profile pattern may be treated as abnormal deviations from the mean.